Apparatus for crushing and pulverizing ore



(ModeL) M. B..,DODGE.

APPARATUS FOR GRUSHING AND PULVERIZING ORES, CEMENT, &c.

No. 262,652. Patented Aug. 15, 1882.

R O T N E v N 1 WITNESSES N. PETERS. Pnolo-Lnho a horl Washington. D. c.

UNITED STATES 1 ATENT rrrcn.

MILES B. DODGE, OF SAN FRANCISCO, CALIFORNIA.

APPARATUS FOR CRUSHING AND PULVERlZlNG ORE, CEMENT, dc.

SPECIFICATION forming part of Letters Patent No. 262,652, dated August15, 1882.

Application filed October 13, 1879. Renewed December 1, 1881. (Model.)

To all whom it may concern Be itknown that I, MILES B. DODGE, of thecity and county of San Francisco, and State of California, have inventedan Apparatus for Crushing and Pulverizing Ore, Cement, 85.0.; and I dohereby declare the following to be a full, clear, anti exact descriptionthereof.

My invention relates to certain improvements in that class ofpulvcrizers in which the ore or cement is crushed or pulverized in arotating cylinder or chamber by means of balls or rocks and mutualattrition of the particles; and it consists in certain details ofconstruction, as hereinafter more fully set forth and claimed.

Figure l is a perspective view of my pulverizer. Fig. 2 is a transversesection.

In certain portions of the gravel-mining regions of California depositsof gold-bearing gravel are found, in which the cement andconglomerations are so hard that the ordinary hydraulic mining operationwill not suffice to separate the gold. It is necessary therefore todrift out the material and crush it under stamps the same as quartz, orotherwise break up the lumps and masses. In doing this they have tocrush also a good deal of material known to contain no gold, but whichis so mixed up with the rest as to be impossible to separate by anymechanical means. This useless material is mainly what is known as Icobble-stonesrounded bowlders of waterworn rock, which contain no gold.They have, however, to be put under the stamps like that portion whichcontains the gold, being cemented in with it.

One object of my improved device is to separate these cobble-stones fromthe auriferons material and throw them to one side, meantime utilizingthem in breaking up the remainder of the cement. In order to accomplishthis, I make a rotary chamber or barrel, A, having two, four, six,eight, or any number of sides, B, said sides being formed of bars a ofiron, with spaces between them, so as to form a grating. Any desirednumber of sides may be made, according to the size of the chamber. Eachone of the sides overlaps the other,

as shown at b, and an opening, C, is made at this overlapping part.

The material is fed in at the end opening, D, and the chamber isrotated, as hereinafter described. The lumps of cement are broken up bythe rotary motion, this action being assisted by the cobbles and piecesof rock which are set free, they acting like balls in the chamber inbreaking up the gravel. All the goldbearin g earth, fine gravel, 850.,are thus set free and pass out of the interstices between the bars intoa sluice beneath, the cobbles, pieces of rock, &c., being retained inthe chamber. To remove this from the chamber I rotate it in the oppositedirection, and these cobbles, rocks, &c.,' will then slide along thesides and out of the openings 0 into another sluice, which carries themoff in another direction. While the gravel, &c., are being ground up thechamber is revolved so that the material slides on the overlapping edgesof the sides past the large openings 0, so the cobbles, rock, 850.,which cannot pass out of the spaces between the bars are retained. Assoon, however, as I commence to revolve the barrel in the oppositedirection these cobbles, &c., are directed toward the large openings 0and pass out, when the operation may be repeated.

By having the revolving chamber made with angular sides, as shown, amore perfect and rapid pulverizing action is obtained. When the chamberis made like a cylinder, perfectly round inside, the material simplyslides around, and is not sufficiently agitated. In this, however, theaction is somewhatlike that of stamps, by the cobbles being lifted up bythe sides, and then thrown down suddenlyon the cement, 860., below. Withthe angular s'ides, however, the material is tumbled over and overirregularly. As one of the sides rises all that material upon it issuddenly thrown down, and is soon covered and pounded by the material onthe next side. In this way all the gravel and cement are thoroughly andrapidly broken up and the auriferous material transferred to the sluice,while the worthless cobbles, rocks, &c., are separated into anothersluice, which may be put in place when the chamber is revolved in theopposite direction. The wear on the grate-bars is very much less in thispounding action than when the material slides over them continually.

Flanges L are formed on the heads of the barrel or chamber to keep it inplace on the rollers M M. On the shafts N N, carrying these rollers, arethe pinions O O, and between them is a gear, P, on the driving-shaft S.With this arrangement of the gears and pulleys, as the driving-shaft isrotated in one direction, the gear 1?, being between the pinions 0 O,rotates both of them in the same direction, and with them the rollers MM, on which the barrel revolves, power being thus applied on both sidesof the barrel at once and insuring its certain action.

In the class of pulverizers for ore, iron balls are usually used forcrushing the ore. The

cylinder is rotated and the balls roll over and over the ore, thuscrushing it. I can, in my device, use metal balls also in crushing ore;but in the peculiar shape of my chamber an advantage is gained overthose which are cylindrical. In cylindrical crushers the balls roll andslide over and over, and the ore slides or drags along the inside of thecylinder, thus wearing out by friction the bars or grates. In mypolygonal chamber the ore is lifted by one of the sides and droppedsuddenly, the balls dropping with it and acting like stamps, pulverizingthe ore by impact rather than by attrition. This facilitates the actionof pulverizing and does not cause so much wear on the grates. Bothgrates and balls are more worn by the sliding than by the droppingaction.

I am aware that rotary cylindrical sitters A rotary crusher composed ofend disks,

and a polygonal crushing-chamber having straight sifting sides, openings0, and overlapping chutes b, all substantially as described. In witnesswhereof I have hereunto set my hand.

MILES B. DODGE. WVitncsses:

S. H. NoURsE, FRANK A. BROOKS.

